Multiple spindle center drive lathe feed mechanism



March 19, 1946.

MULTIPLE SPINDLE CENTER DRIVE LATHE FEED MECHANISM W. F. GROENE HALOriginal Filed June 20, 1942 4 12 Sheets-Sheet 1 F-IE. l

l l l l I N VEN TORS.

WILUAM EGROENE 'BY ARTHUR w. AUFDERHAR ATToRNEs W. F. GROENE ET AL.

Ma'rch 19, 1946.

12 shets-sheet 2' Original Filed June 20. 1942 Nil QM n l I l I l l l ll I |Jl l l l l l l l I l l lllnnlvc l I l I l l l l I I I I," u.. f-laf l@ -L lllllllllllllllllllllllllllllllllllllllllll ||J em. :Ill`|H||Ill||||l|||ll|ll|ll l I I l I |\M l m., .E E E l wm wj E v n VT T|-.m H. Hf -mrf v .mm mmm 3\ k f il( F.. n ix u m; 7-

INVENTORS. WILLHM F. GROENE ARTHUR W. AUFDERHR BY ATTORNEYS w. F. GRQENEET AL 2,396,784

MULTIPLE SPINDLE CENTER DRIVE LATHE MECHANISM March 19, 1946.

original Filed June 20, 1942 12 Sheets-sheet s 3 c. m M ),1. :l: a@

FIB-D1 INVENToRs. .wlLLlAM F. GROENE BY ARTHUR W. RUFDERHRR ATTORNEYSMarch 19, 1946. w. F. GROENE ETAL 2,396,784 MULTIPLE -SPINDLE CENTERDRIVE LATHE FEED MECHANISM y Original Filed June 20, 1942 12Shets-Sheei'I 4 3 33 l 'l v 5 56 Y T T- o \'l ff" y HE. ISI

- 1 INVENToRs. WILLMM EQROENE .BY ARTHUR W. NIFDERHR March'l9, 1946; w.F.' GROENE Erm. 2,396,784

` y `MULTIPLE SPINDLE CENTER `D-RIVE LATHE FEED MECHANISM I Origi'nal.Filed June 20, 1942 L 12 Sheets-'Sheet 5 l Xl L s .`\we

-ss We INVENTORS. WILLIAM F. GROENE ARTHUR W. RUFDERHAR ATTORNEYS I-TBEw. F'. GROENE ErAL. 2,396,784` MULTIPLE SPINDLE CENTER DRIVE LATHE FEEDMECHANISM I March 19, 194e, 4

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March 19, 1946. w.I F. GROENE Erm. 2,396,734 l MULTIPLE SPINDLE CENTERDRIVE LATHE FEED MECHANISM Original Fled June 20, 1942 12 Sheets-Shea?I8 umani-:15.

` March 19, 1946.

w. F. GROENE ErAL MULTIPLE SPINDLE CENTER DRIVE LTHE FEED MECHANISMOriginal Filed June 20, 1942 12 sheets-sheet 9 BY. ARTHUR w.AuFi ERHARVINVINTORS. WILLIAM F. GROENE ATTORNEYS l March 19, 1946. w. F, @Rol-:NEHAL 2,396,784`

MULTIPLE SPINDLE CENTER DRIVE LATHE FEED MECHANISM.

' originai Filed June 2o, 1942 12 sheets-sheet io lNvENroRs.' WILLIAM F.GROENE WAUFDERHAR Mw 5M ATTORNEYS March 19, 1946.

W. F. GROENE ETAL MULTIPLE SPINDLE CENTER DRIVE LATHE FEED MECHANI AOriginal Filed Ju-ne 20, 1942 v l2 Sheets-Sheet 11 SEA S .vm H ".l..

n T, Il MW FH E ma. E u@ LH. Y `m L ITv wm Maw-h 19, 1946.

w. F. GRQEN r-:rAL 2,395,784;

MULTIPLE SPINDLE CENTER DRIVE LAIHE vFEED MECHANISM Origine-.1 FiledJune 20, 1942 12 Sheets-Sheet 12 INVENToRsL WILL/AM F. ARTHUR w.

GROENE BY AUFDERHAR TJ@ *TM ATTORNEYS.

Patented Mar. 19, 1946 MULTIPLE srINDLE CENTER DEivE LA'rnE FEEDMECEANISM William F. Groene and Arthur W. Aufderhar, Cincinnati, Ohio,assignors to The R. K. Le Blond Machine Tool Co., Cincinnati, Ohio, acorporation of Delaware Original application June 20, 1942, Serial No.

447,810. Divided and this application Decem ber 18, 1943, Serial No.514,732

9 Claims.

This application is a division of our application Serial No. 447,810,filed June 20, 1942, and assigned to the same assignee as the presentapplication.

This invention pertains primarily to multiple spindle lathes of thecenter drive typein which a plurality of work pieces are chucked androtated by means of center drive chucking mechanism and are supportedrotatively on their ends by means of the usual tailstock centers of suchcenter drive lathes. In lathes of the center drive type it has alwaysbeen a problem to load the work pieces past the tailstock into thecenter drive chuck. This problem becomes much more complicated when aplurality of center drive work spindles are to beutilized. Thisdifficulty is brought about by the presence of a plurality of tailstockswhich must be associated with the center drive chucks and which must berelatively closely spaced to 4effect an overall size for the machineWell within its range of efficient operation and manipulation by theoperator. As a result it has been diicult to effect the loading of eachof the work pieces for each of the center drive work spindles past theirrespective tailstocks and it is one of the chief objects of thisinvention to obviate this difliculty by providing a single unitaryhousing for all of the tailstock centers xed on the frame of the latheand to provide operations and facing operations simultaneously f at allof the work spindles of the machine with appropriate tool feedingdevices having passageways in susbtantial augment with the passage- Waysin the tailstock housings of the lathe to permit proper loading of thework therein. It;

is also a further object to provide facing tools located on the housingfor the tailstocks of the machine which may be moved to and from thework radially to effect necessary forming and facing operations desiredon the work pieces.

It is also an object to arrange the machine with facing tool feedingdevices mounted on the housings of the tailstocks with passagewaysthrough the tailstock housings so that the work may be efficiently andeasily loaded into the machine without interference with the cuttingtools and tailstocks and without preventing proper access to said toolsand the work pieces by the operator.

A further object of this invention is to provlde in a multiple spindlecenter drive lathe an arrangement in which all of the work spindles aremounted in a vertical plane, spaced one above the other and to provideappropriate feeding mechanism in which there is a tool releasearrangement provided for the turning tools which functions vertically tomove the turning tools into and out of work operating position and toalso provide in conjunction with such turning tool feeding mechanism,facingv tools which are pivotally mounted on the tailstock housings ofthe machine which may also be simultaneously fed radially to and fromthe work pieces of the various work spindles.

It is a further object of this invention to effect vthe lstraightturning, taper turning, and facing operations of the various cuttingtool feeding devices from cam mechanism located on top of the machinefor accessibility and fr'ee from the cutting coolant and chips of themachine during its operation, said cam feeding mechanism being locatedwell above all of the vertically arranged work spindles of the machine.

Further features and advantages of this ivention Will appear fromthe'detailed descriptions of the drawings in which:

Figure I is a front elevational View of the multiple spindle centerdrive lathe of this invention, particularly showing the location of thecenter drive work spindle housing, the end tailstock housing, theloading passageways through the tailstock housing for axial insertion ofthe work pieces in the center drive chucks on the work spindle, and alsoshowing the swinging facing tools mounted on the tailstock housing.

Figure II is a rear elevational view of the machine shown in Figure I,particularly showing the main drive motor forrotating the work spindles,the tool relief cam mechanism for the turning tool slides, and the fluidpressure actuating cylinders for operating the centers in the left handtailstock.

Figure III, a left hand end elevational view of the machine of Figures Iand II, particularly showing the belted motor drive connection forrotating the work spindles, and the loading passageways formed in thehousing carrying the left hand tailstock centers.

Figure IV is a right hand end elevational View of the machine of FiguresI and II particularly showing the hydraulic lever operated mechanism formoving the centers for the right hand tailstocks of the machine and alsothe loading passageways through the housings for these tailstocks.

Figure V is a vertical transverse section, shown on the line V-V-of`.Figures I,II-and-VI, par ticularly showing the relationship ofthejturning tools on the turning tool slide, the taper attachmentmechanism of the turning tool slides, and the swinging facing toolsmounted on the tailstock housing.

Figure VI is a fragmentary enlarged plan YView of the machines ofFigures I and II particularly showing the cam feeding mechanism the camtool relief means for the turning tools, van'dishowing the applicationof the facing tools to a work piece in the top work spindle ofthemachine.

Figure VII is an enlarged fragmentary transverse section through themachine on the lines VII-VII of Figures I, II, VI, and IX, particularlyshowing the rack and the pinion actuatingmechanism for eecting theturning feeding movement for the turning tool slide.

Figure VIII is an enlarged fragmentary ltrans-- verse view through themachine on the line VIII- VIII of Figures I, II, VI, and IX,particularly showing the cam actuating mechanisms for simultaneouslymoving al1 of the basic'tool feeding devices to and from the work.

Figure IX is an enlarged fragmentary horizontal section through one ofthe right hand tailstocks which are operated by hydraulic pressure asshown. on the line IX-IX of Figures I, II, and IV, showing'the hydraulicactuating cylinder for axially reciprocating thevtailstock barrel andcenter when loading and unloading Work in the-machine tool.

Figure X is a diagrammatic view showing the application of the `turningtools to .a work piece mounted in the lathe, indicating the specificoperations undertaken by 4said tools.

Figure XI is a similar diagrammatic view to that of Figure X but showingthe facing tools operating upon a typical work piece mounted in thelathe, indicated on the line IQI-XI of vFigure V.

Figure XII is an enlarged diagrammatic view of the feeding mechanismVfor the turning tool slides.

Figure XIII is a fragmentary diagrammatic front elevation Yof themachine shown'inFigureI, with the -tool feeding devices removed, to moreclearly vshow the manipulation of the work into and out of workingposition on the vvarious work spindles ofthe machine.

yFigure XIV is a diagrammatic layout showing' the relationship of vthevarious operative elements of the tool relief and feeding mechanism ofthe machine.

The machine comprises a base I upon which is mounted the frame2, towhich isiixed the center drivework spindle housing 3, the leftnhandtailstock housing 4 and the right hand vtailstock housing v5. Y Y

In the center drive housing 3 is journaledthree center drive workspindles 6, "I, and 8 each having appropriate chucking means 9 forgripping and holding workrpieces, in this case comprisinganautomobileaxle shaft. These work spindles-6, I, and `'8 have appropriatering gears I0, II and I2 respectively asin conventional practiceforcenter drive work spindles, and each-of these 4ring gearsV I D, IIand I2 are interconnected hy-suit-Y able'idler pinions I3 and I4respectively appropriately iournaledin thecenter drive housing 3 sothatall of the work spindles I0, II and .I2-Will be rotated simultaneouslyin the same direction. All of these work spindles are driven by the maindrive motor I5, Figure V which is appropriately mounted on a motor plateI6 mounted on a suitable pin I'I on -the base .-i of the-machine andvwhich is adjustable by suitablejscrew wfor effecting proper tension inthe driving belt I9 which operates over the motor pulley 29 and the maindrive pulley 2I fixed on the main drive shaft 22 journaled appropriatelyin the left hand end of the base I in a suitable bearing 23 andsupported atits-inner end in the projecting downward portion 24er thecenter drive housing 3. This drive shaftl 22 'has an appropriate drivingpinion 25 whichdrives anidler gear 28 journaled in center drive housing3 which gear 26 in turn is connected 'in driving relationship with thecenter drive gear I2 on A'the lowest work spindle. In this way drivingaction from the motor I5 effects rotation of the various center drivework spindles 6, 1, and 8 at the appropriate cutting speeds necessary tomachine the work pieces W.

I'n`the left hand tailstock housing is mounted the usual tailstockbarrels 21 each of which is axially reciprocable by a conventional screwand nut mechanism vactuated by rotating the squared end portionslof therespective actuatingmechanism for each of the tailstock barrels 2'I, andappropriate centers 29, 30, and 3I are provided in each'of the tailstockbarrels 2l and these centers appropriately engage centerholes-in the endof the work pieces W.

The right hand tailstock housing similarly has axiallyreciprocabletailstock barrels 32 which are actuated by hydraulicpressure, best seen inFigure IX, through'theimedium of a fluid pressurecylinder 33 fixed 'to the frame 2 by suitable screws 34 and havingtheusual actuating piston 35 and piston rod 3E 'which is 'connected to thelever 31 carried on a pivot pin 38 'fixed to a bracket 39 on theframe 2fand having an outer end portion with apin '4U operating in avspoolv4Iadjustably threaded by suitable `means y42 into the tailstock barrel 32.so that reciprocation of the piston 35 in cylinder 33 effectsengagementor disengagement of 'the center r'II3 carried 'in thetailstock barrel32`with thework to facilitate rapid .loading and"unloading of the work lin the machine. The centers 29 'in 'the lefthand tails'tock vbeing normally heldin fixed position after properadjustment by 'rotating the 'means 28 'to thereby axiallylengthwise'positionthe work pieces properly on the work spindles withrespect to the cutting tools and the center drive chucksr 9.

`When the piston 35 in the'cylinder 33 is so'actuated to 'have withdrawnthecenters 43 to the right in the'Figures I and IX and withithe'cuttingtools appropriately retracted from the Vwork as will` be describedlater, the machine is'then in conditionrfor loadingand unloadingwork-pieces W intothe various' workspindles.

With regard-to themethod o'ffloading the work W in tlevariou'sworkfspindles'it'is to be noted that both 'So'f the Vtailstock*housings4 and 'S'are one Yunit teach vrespectively housing their threetailstockba'rrels in a rsingle member rigidly fixed -to the frame 2`ofthe machine. It is, therefore. necessary to 'provide satisfactory andadequate means to permit easy insertion ofthe workr pieces W into thework spindle,particularly"whenrthere are a plurality of them involved asin this case. In so far as the'topwork spindle-E is vconcerned the workW'- is loaded over the top "of the `upper tailstock barrel 2l Pand -43'over tlieisurface 144 of --bothof these Vtailstock housings II and'B-there being adequate room in thecenter drive chucks 9 to permitappropriate tipping of the work piece W from the exact alignment andparallelism with the work spindle axis of each of the work spindles.However, in the lower spindles 1 and 8, access to them for axial loadingofthe work therein is provided by means of the loading and unloadingpassageways 45 and 46 respectively for the two lower work spindles.Ordinarily in the operation of this machine it is the customary practicerst to load the work spindle by insertion of the work either over thesurface 44 of the tailstock housing 5 and through the openings 45 and 46of this housing to present the work to the centers 29, 30 and 3| andthen to insert the cenn ters 43 for the other tailstock barrels 32 bymanipulation of the hydraulic cylinder 33 as described. After the workis completed the work in the upper spindle is then moved out over thesurface 44 of the left hand tailstock housing 4 and the lower workspindles are relieved of their work pieces W by passing them axially outthrough the passageways 45 and 46. The machine is then ready forreinsertion of new unmachined work pieces over the surface 44 andthrough the passageways 45 and 46 of the right hand tailstock housing 5and feeding the cycle as described is again resumed.

This method of handling the work into and out of the machine is bestillustrated in Figure XIII wherein is shown the work at position W-l onthe right hand side of the machine as it is initially placed on thesurface 44 and in the holes 45 and 46 of the right hand tailstockhousing 5. The work is then moved along to the position W-'2 for each ofthe work spindles with its left hand end inserted into the chuckingdevices 9 while their clamping jaws 9a have been moved to withdrawnposition by the clamping bolt 9b of the chucks 9, Figure V, to permitplacing of the f work into the chuck and into the bore 8cof therespective center drive work spindles 6, 1, and 8. The work is thencontinued to. be moved to the position W-3 and properly mounted on thecenters 29 and 43 by moving the tailstock barrels 32 to engage thecenters 43 with the ends of the work W. The chuck clamping screw 9b isoperated to clamp the work W against the fixed work engaging abutmentjaws 9a, Figure V, of the chucks 9, ready to begin the cuttingoperation.

At the completion of the cutting operation the centers 43 are removedfrom the work W and the work is moved from position W--3 to position W-4with the chucks 9, of course, released from the work. From position W-4the work is then moved to the final position W-5 where it is removedfrorn the machine. In this last position W-5 it ispositioned on thesurface 44 and in the passageways 45 and 46 of the left hand tailstockhousing 4. It is, of course, obvious that the work could be loaded fromleft to right as well as from right to left as above described dependingupon the desires of the operator and the arrangement of the machine inthe line-up in the manufacturing plant.

By means of this unique construction it is possible to provide a unitaryrigid housing carrying the tailstock barrels for both the right and lefthand sides of the machine while at the same time providing adequatepassageway for easy loading of the work pieces into the various workspindles, and in particular the two lower spindles in this illustrativedesign, without requiring any movement tothe tailstock housings It isvalso tol benoted that these'pas'sageways are arranged in the form of -asleeve 41 so as to maintain the operating mechanism in the tailstockhousings totally enclosed at all times and free of foreign matter `orother dirt or chips which may come from the work in loading it throughthe various passageways 45 and 46.

Referring particularly to Figure X, in this exemplary embodiment of thisinvention there are a series of straight turning tools 48 and 49 pro-`vided Afor turning the straight diameter portions 50 and 5| respectivelyon the work W; a series of taper turning tools 52 which are arranged toturn the tapered portion 53 of the work W; and there is also cooperatingwith these turning tools above, facing tools vor tools feeding radiallyor perpendicular to the axis of rotation of the work comprising thecutting tool 54 for chamfering one end of the shaft adjacent to theportion 5| and the forming tool 55 which completes the facing andnecking operations with respect to the portions 5| and 53 of the workpiece W.

The cutting tools of Figure X do the turning operations on the work,that is, they have feeding substantially parallel .to the axis ofrotation of the work W, and are carried in the respective tool holders56 for the tools 48, 51 for the tools 49, and the tool holder 58 for thetaper turning tools 52. There of course is a series of these tools 48,49, and 52 for each of the work spindles 6, and 8 of the machine andvtheir respective tool holders 56, 51, and 58 are mounted on appropriatetool slides which effect their feeding motion in turning the work andalso have a tool relief motion perpendicular to said feeding motionwhereby the tools may be retracted perpendicularly away from the workspindle axis to prevent marring of the work after the tools have oncepassed over the Work to complete their turning operations. Tool holders56 with their respective turning tools 48 are rigidly fixed on a plate59 which is rigidly connected to the feeding slide 60 by suitable screws6| and the spaces formed by the tool blocks, 56, 51, and 58 on theirrespective slides 59, 62 and 64 provide passageways in substantialalignment with the tailstock passageways 44, 45 and 46. Similarly thetool holders 51 are likewise mounted on a member 62 securely xed to thissaine feeding slide 60 by suitable screws 63 so that horizonta1 movementof the slide 66 eects similar horizontal feeding movement in the toolholders, 56'

and 51 and their respective tools. The taper turning tools 52 arecarried in their respective tool blocks 58 for each work spindle, whichblocks are 'i xed to a sliding bar member 64 which has vertical slidingmovement in a suitable dovetail guideway 65 on the feeding slide 66 andthis vertical sliding movement is controlled by the taper attachment bar61 in which operates a sliding Ishoe 68 carried on a suitable pin 69fixed to the member 64 so that as this member1 64 moves horizontally thecutting tool 52 will vbe caused to follow a tapered path in accordancewith the taper` set on the taper attachment bar 61.

The feeding slide 60 is carried in appropriate dovetail guideways 10 inthe tool relief member 1| and carried in appropriate dovetail guideways12 in the tool relief member 13; the tool relief members 1| and 13 beingappropriately mounted in the respective dovetail guideways 14 and 15 inthe frame 2 of the machine. Each of these tool relief members 1| and 13are maintained either in a lowered position or tool relief position withthe tools away from cutting position with respect tothe work piece W orin a raised or cuttingposition for the `tools bythe engagement of therollers 16, Figure II, carried on .appropriate pins 11 fixed in each ofthe members 1| and .13 and which rollers operate on; the identical toolrelief cams T8 which cam is :horizontally reciprocable in an appropriateguideway 19 formed in the top of the frame 2, by means .of the,tool-relief hydraulic cylinder 80 .having theV usual piston rod 8|appropriately connected at 82 to the cam T8' so that by reciprocation of.the cylinder 88 the tool relief slides 1| 'and 'I3 are simultaneouslymoved to cutting position or to retracted position. The feedingorturning feeding vmotion provided for the tools 48, 49 and 52 iseffected `by actuation of the box shaped feeding slide 83 appropriatelymounted in suitable guideways 84 lformed in :the top of the frame 2 ofthemachine, this box-shaped feeding member being reciprocated in` saidguide- Ways .by means of the hydraulic yfeed cylinder 85 bolted to thetop ofthe frame 2 of the -machine by suitable screws 88and having amovable-piston rod 81 appropriately connected at 88 to the boxshapedmember 83. At the leftend of this boxshaped member and tothe rear of itis fixed va rack 89 which actuates the rack .pinion V98 fixed on theshaft 9| appropriately journaled .in the frame 2 of the machine andhaving on its lower end a pinion 92 which operates in a rack93 xed tothe feed slide 60.

Similarly, at the otherend `of the box-shaped feeding member 83 is fixedthe rack 94 which actuates the pinion 95 fixed on the shaft 9Bappropriately journaled in the frame 2 of the machine and having on itslower end a pinion Si which operates in the rack 98 fixed to the feeding:slide 68. Itis therefore apparent that operation of the 4hydrauliccylinder 85 ito effect sliding movement in the box-shaped member 83 willcause appropriate rotation of the shafts 9| and 96 through the medium oftheir pinions 92 and 91 respectively feed the feeding slides |58 and 66toward or vawatr from each other -to effect the necessary turningoperations of their respective cutting tools 48, 49, and 52 on the workW. The pinions vand racks 92-93 and 91-98 are .provided sumciently wideto permit the raising and lowering of the imembers 1| and 13 in toolrelief movement whilestili maintaining proper feed engagement of themember "83 with the various tool feedingslidesand 6B so that the toolsmay be retracted from their fed-in positions when the members 1| and`'I3 have relieved the tools from cutting laction with the work and `maythen bring the tools back'to-.a cutting position when the feeding slideshaveremoved the tools from the starting .position for 'again continuingthe cutting cycle of the. machine.

Obviously, movement of the slide A66 horizontally in the guideways 12ain the member 13 .will cause the tool block .supporting member `Matohave vslight vertical movement in addition to `its horizontal feedingmovement `as `effected bythe slide 66, to .in this 'Way effect the taperturning motion in the tools 52 for machining the tapered essaim shapedfeeding member 83by means of the cams |02, Figures VI and VIII, whicharexed on this member 83 and which cams actuate rollers |83 carried onappropriate studs |94 fixed to the vertical actuating rods |85, whichrods have approprate slots |95 ilu-which operate the pins |81 on thelever arms |88 xed to the rock feeding shafts |'|l| k.so thatreciprocation of the member 83 causes rocking motion of the levers |88and corresponding rocking Vmotionin the tool holders 99 and |110 yforswinging the facing tools 54, 55 to-or from the work piece W.

'Having .thus fully set forth and described this invention what isclaimed as new and desired to secured by United States Letters VPatentis:

1. In a lathe, a frame having Work spindles in which a Work piece may bemounted and rotated on a work axis, a tool relief slide mounted fortranslation onsaid frame toward and from said axis, a second reliefslide mounted on said frame for translation parallel to said firstframe, there being aligned ways on said slides parallel to said axis, afeeding slide mounted by and for translation along both of said ways, asecond feeding slide mounted by and for translation along the Ways ofone feeding slide only, tool holders carried by said feeding slides,first power means connected to translate said relief slides, and secondpower means connected to translate said tool feeding slides for allpositions of translation of said relief slides.

2. In a lathe, a frame, spindles on said frame and adapted to journal awork piece therebetween forrotation on an axis, a tool reliefslidemounted for translation on said frame toward and from said axis, afeeding slide mounted on said relief slide for movement along said axis,said feeding slide being adapted to mount cutting tools for movement incutting relation with a work piece in said spindles, a first rack onsaid feeding slide, a shaft journaled in said frame and having lrst andsecond pinions thereon, an operating slide translatable on said framenormal to the axis of said shaft, a second rack on said operating slide,said rst and second pinions meshing with said first and second racks,respectively.

3'. In a lathe, a frame, spindles journaled on said frame to receive awork piece for rotation on an axis, a tool relief slide mounted on saidframe for sliding toward and from said axis, a feeding slide mounted onsaid relief slide for translation along and adjacent said axis andadapted to xedly carry cutting tools for cutting a work piece rotatingon said spindles, atrack on said frame, a cam `sld'able along saidtrack, and vmeans attached to said relief slide and controlled by saidcam `to positively move said relief slide in relief movement.

34. In a lathe, a frame, a plurality of pairs of work spindles on saidframe each pair being positioned to receive .a .work piece therebetweenfor rotation von horizontal, superposed Work axes, a tool relief slidevertically translatable on ways on said frame, a feeding slidetranslatable on said relief slide along said axes, a tool holder platexed on said feeding slide Aand adapted to hold tools .in simultaneouscutting engagement with said respective work pieces, cam means operabletotranslate said Vrelief slide, and means operable to translate saidfeeding slide on said relief slide for `allposition of translation ofsaid relief slide.

v5. In a` taper-cutting lathe, a frame having means to receive androtate a work piece on an axis-a first slide guided on' said frame fortranslation toward and from said axis, a second slide on said rst slideand guided thereby for movement parallel to said axis, a third slide onsaid second slide and guided thereby for translation toward and fromsaid axis, tool holder means on said third slide, cam track means on oneof said rst and third slides and a shoe on the other of said first andthird slides engaging said track means, means for translating saidsecond slide to thereby cause taper feeding movement of said thirdslide, and means for translating all of said slides as a unit from saidaxis in too1 relief movement.

6. In a taper cutting lathe, a frame having means to receive and rotatea work piece on an axis, a too1 relief slide guided on said frame formovement toward and from said axis, a feeding member guided on saidrelief slide for movement parallel to said axis, a too1 slide guided onsaid feeding member for movement toward and from said axis and adaptedto hold a tool for cutting a work piece, taper cam and shoe meansinterposed between said slides whereby said tool slide is given ataper-cutting movement as said feeding member is moved on said reliefslide, means for so moving said feeding member, and means for movingsaid relief slide whereby said feeding member, and too1 slide are movedas a unit toward and from said axis.

7. In a lathe, a frame having means to receive and rotate a work pieceabout an axis, a pair of relief slides, guide means mounting said slideson said frame for translation toward and from said axis, power operatedmeans for so translating said slides equally and in unison, a feedingslide guided on and by said relief slides for translation in a pathparallel to said axis, a too1 holder carried by said feeding slide, asecond feeding slide guided on and by one of said relief slides fortranslation in said path, a power-operated slide, and connectionsbetween said power-operated slide and said feeding slides for movingsaid feeding slides simultaneously along said path.

` 8. In a lathe, a frame having means to receive and rotate a work pieceon an axis xed relatively thereto, a tool relief means slidable on saidframe toward and from said axis and having guide means defining a pathparallel to said axis, a pair of feeding slides guided for translationalong said path by said guide means, tool holders carried by saidfeeding slides, each feeding slide having a rack parallel to said path,parallel shafts journaled on said frame, each having a pinion meshingwith a respective rack, a power slide guided on said frame in a pathnormal to said shafts, racks on said power slide, and second pinions onsaid shafts each in mesh with a respective rack on said power slide.

9. In a lathe, a frame having means to receive and rotate a work pieceon an axis, tool relief means guided on said frame for translationtoward and from said axis, said tool relief means having guide meansdetermining a path extending along said axis, a pair of feeding slidesguided by said guide means for movement along said path, holders fixedto said feeding slides andl adapted to grip tools for cutting a workpiece, power means operable to simultaneously move said feeding slidesalong said path, in opposite directions, and cam and-rider meansoperable to translate said tool relief means relatively to said framewhereby said feeding slides and holders are moved as a unit in toolrelief movement.

WILLIAM F. GROENE. ARTHUR W. AUFDERHAR.

